This invention pertains to the electrical power flow monitoring art, and, in particular, to a bidirectional power flow wattmeter.
Wattmeters adapted for measuring power flow along a line are well known in the art. Conventionally, wattmeters include a housing having jacks thereon for connection to the power line to be monitored. A coupler, which senses the power level on the line, is inserted within a housing aperture. In response to the A.C. power level sensed by the coupler, detection circuitry within the coupler generates a D.C. signal which in turn drives a D.C. meter, calibrated in power units, located within the housing. Such wattmeters have been inherently unidirectional, i.e. they measure net flow in one direction of the line at a time. When concurrent power flow in the opposite line direction is to be monitored, the power line connections to the wattmeter must be reversed.
Such prior art wattmeters are inconvenient to use. Whenever power along a given line is measured, the line must be broken and connected to the power meter, requiring a lengthy cessation in power flow. This is especially inconvenient in radio frequency transmitters, wherein a transmitting station must go off the air before power may be measured. Additionally, due to their unidirectional nature, prior art wattmeters do not provide a quick and convenient indication of forward and reverse power flow along the line.